Try setting log_level to 5. I haven't seen a single WLCEVENTD message with that log_level.
Code:
nvram set log_level=6;nvram commit;reboot
I first installed 385.10000 on my 68U repeater and got lots of WLCEVENTD messages (every time a client connected or disconnected). When I installed 385.10000 on my 68U main router, I didn't see any of those messages. When I checked for differences in log_level, I saw that I had (long ago) set the main router's log_level to 6. So I set it to 6 in the repeater and rebooted. No more WLCEVENTD!
I still get the normal (routine) logging such as service restarts, log-in attempts, etc.